Conditions necessary for cell culture
The in vitro growth of cells requires that certain physico-chemical parameters are maintained. Various cell lines require different conditions during cultivation. Some cells are adherent and require an attachment substrate, while others grow suspended in cell culture media. A general cell culture environment includes cell culture media for nutrient supply and gases like oxygen and carbon dioxide. Culture vessels are also needed.
Cell culture vessels
Cell culture vessels come in various formats such as dishes and flasks, both of which are often used in life sciences research labs. However, bioreactors are the preferred systems when making a therapy based on monoclonal antibodies (mAbs) or other molecule type. Bioreactors help regulate the artificial environment for process control and efficiency.
Types of bioreactors
Bioreactors come in different configurations and sizes to suit various bioprocessing needs and scales. Multiple-use models allow reuse after thorough cleaning and sanitization. On the other hand, single-use bioreactors operate under functionally closed conditions and use sterile biocontainers to minimize the risk of contamination by microbes.
The material used to make multi-use bioreactors varies depending on scale. Small-scale cell cultures often occur in glass systems that can be sterilized using an autoclave. For larger scale cell culture, stainless steel bioreactors are used. These systems are designed to be used with cleaning in place (CIP) and sterilization in place (SIP) between bioreactor runs.
There are several types of bioreactors:
- Stirred tank bioreactors: These automated systems come with an impeller that helps to keep cells suspended in the nutrient-rich medium. They also have components to control the aeration with oxygen and to release carbon dioxide waste. Stirred-tank reactors (STRs) are the most common bioreactors for bioprocessing. These can be stainless steel in sizes up to 20 000 L or single-use bioreactors up to 2000 L.
- Rocker bioreactor: A rocker bioreactor is a rocking platform that uses a disposable, single-use bag and control system to keep cells in suspension and growing optimally. The working volume is up to 25 liters for a manufacturing process in a non-GMP or a GMP environment.
- Fixed-bed bioreactors: These systems support growth of adherent cells that require an attachment surface, without the need to add beads such as microcarriers.
Rocker bioreactor FAQs
What is a rocking bioreactor?
Rocking motion bioreactor systems promote high cell densities when operated in fed-batch or perfusion mode. They’re particularly useful for seed train applications prior to growing cells in the final stirred-tank bioreactor. Rocking platforms are also well-suited to growing sensitive cells and large particles, such as viruses, that are sensitive to shear.
What are single-use bioreactors?
Single-use bioreactors are versatile bioreactor systems with disposable bags that help limit contamination and save time during cell culture and biomanufacturing. Single-use bioreactors include stirred-tank and rocking options; both are automated for process control.
What is a wave bag?
A WAVE™ bag is a disposable bag used in a ReadyToProcess WAVE™ bioreactor. The bag is configured for easy aseptic connection to single-use tubing and other single-use components. It requires no cleaning and limits the risk of contamination.